Access opening for use in aircraft construction



May 28, 1935.

c. E. HATHORN ACCESS OPENING FOR USE IN AIRCRAFT CONSTRUCTION Filed July 15, 1932 UNITED STATES PATENT OFFICE ACCESS OPENING FOR USE IN AIRCRAFT CONSTRUCTION Charles E. .Hathorn, Hempstead, N. Y., assignor to Curtiss Aeroplane & Motor Company, Inc., a corporation of New York a Application July 15, 1932, Serial No. 622,633

Claims. (Cl. 244-31) The present invention relates generally to acful operation of the fastener was thereby decess openings for use in aircraft construction and stroyed. and the hooks of the fastening device more specifically toan improvement in the maneither become seriously damaged or actually ner of constructing such an opening so as to perpulled out of the webbing material.

5 mit the use of slide fasteners in connection there- It is therefore an object of the present inven- 5 with. V v tion to provide a door in the cover of an airplane It is essential that certain openings be emfuselage or other body which may be readily bodied in the surfaces of an aircraft, as in the opened or closed by means of a slide fastener. sides of the fuselage or wings of a heavier-than- Another object of the invention resides in the air machine, to allow convenient access to mail, provision of a door in the cover of an airplane 10 baggage and other compartments or equipment. fuselage adapted to be readily opened or closed Inspection doors and hand hole openings become by means of a single continuous slide fastener a necessity wherever periodical inspection and which may comprise either acurved, or astraight, maintenance of particular localities or parts of or a combination of both curved and straight an aircraft structure are required. Since these sections depending upon the shape of the open- 15 openings are necessarily of various shapes and ing closed by the door. sizes and are located in different parts of the It is also an object of the present invention fuselage or wing covering which are seldom of to provide a door of practically any size or shape the same shape or curvature, the merit in an in the cover of an'airplane fuselage, adapted to adaptation of some standard, readily operated, be opened or closed by means of one or more slide 20 fastening device to all such openings regardless. fasteners, in which the operation of the fasteners of their size, shape or location has been previwill not be affected by the tightening or shrinkage ously recognized, and as a result several unsucof the fabric cover of the fuselage. cessful attempts have been made to utilize the A further object of my invention is to provide well known continuous sliding type of fastener a framing of metal orother material secured to 25 as such a closure. All of these prior structures, and sopositioned with respect to the edges of however, have been abandoned due to specific the door and to the edges of the opening in the fa lures which, in most cases, have been attribfabric fuselage cover as to render it practicable uted to the inability of this type of fastener to to use a single fastener for closing the opening,

39 Withstand the stress imposed upon it under con- Whether the opening be triangular, circular, semiditions of service to which it has been subjected. circular, rectangular with curved corners, or of This has been particularly true whenever an at any other shape.

tempt has been made to use this type of fasten- Another object of the present invention is to ing device in connection with a fabric door in a adapt'such a framing to the door and to the fabric covered fuselage or other body. sides of the opening, designed to be closed by the 35 There has apparently been an entire lack of door by means of a slide fastener, which may appreciation on the part of prior inventors of either be curved or straight, in such a manner the fact that the real reason underlying their that the door will be-flush or nearly so with the failures has resided not in any weakness of the surrounding cover when in a closed position.

40 fastening device, but in a characteristic of the Stlllafurther object of my invention is to shape 40 fabric covering itself which they have neglected each of such frame members in the form of a to take into account, namely, thata dopeimpregtruss so that a strength to weight ratio of the nated fabric cover shrinks very appreciably after same will be consistent with the requirements of it has been applied to the fuselage, or other aircraftconstruction'and with theuse which is framework, so that it tightens to such an extent to be made of such parts. In case the frames are 45 that eventually the fasteners are pulled apart or formed by stamping from the same piece of metal become broken and inoperative. Inthis connecor other material, the inner frame may be made tion it should be noted that when laced or any from the waste of the center of the outer frame other type of fabric doors are allowed to remain resulting in low cost of manufacture. No waste open for any length of time, it is practically imoccurs because practically all of the material is 50 possible to completely close them again due to utilized. the shrinkage of the, fabric. It has also been Other not less important objects such as the customary to paint the webbing of the fastener manner of assembling the unit and of sewing the to match the color of the fuselage cover without frame to the door and to the fuselage covering realizing that the flexibility required for successmaterial, will appear from the following speciflcation in which an acceptable embodiment of invention is fully described, claimed and illustrated by way of an example only, it being understood that the invention is susceptible of modification in accordance with suggestions herein contained and within the scope of appended claims.

In the drawing:

Fig. 1 of the drawing shows my invention applied to various types of openings in the side of an airplane fuselage;

Fig. 2 is a plan view of the triangular form of the device shown in Fig. 1, the door being in closed position;

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 2.

Referring more specifically to the drawing, in which similar characters of reference indicate corresponding parts in all the views, Fig. l is a view in elevation of an airplane l of conventional bi-plane type showing three openings of different sizes and shapes in the sides of the fuselage thereof, each ofsuch openings being provided with a door constructed in accordance with my invention. At the side of the cockpit is located a triangular-shaped modification of my invention, shown at A, as for the purpose of providing access to a particular part of the fuselage for inspection or repair. B represents another adaptation of my invention to a larger type of openingwhich may be rectangular with rounded corners or of other shape such as the door to a baggage compartment, whereas 0 shows an approximately semi-circular opening located at the rear of the fuselage near the empennage of the airplane in connection with which the invention such an extent that the fasteners either fail or become inoperative. This would obviously be the case also whenever doped fabric or other material having similar characteristics dependent upon temperature or weather conditions is used either for the door or for the covering of the fuselage. In the present invention, this fault is overcome, and such an installation and use is made entirely practical and desirable, by the utilization of light weight frames secured both to the door and to the edges of the covering as shown in detail in Figs. 2 and 3 of the drawing, which illustrate for purposes of description the triangular-shaped opening A, it being understood that the principles and features of construction comprehended by the invention are equally as applicable to openings of the type of B and C as well as to other openings of various sizes and shapes and for different purposes as may occur to a person skilled in the art from reading this specification.

.In Figs. 2 and 3, the fuselage or other body covering III is cut out to form a door H, to the edges of which is secured a web l2 which carries slide fastener M will open or closethe device in a well known manner depending upon the direction of movement imparted to the member l4. When it is desired to use the invention in connection with a fabric body covering, the webs l2 and I6 may be sewed directly to the covering and to the door by stitches as shown at I! and I8. Inasmuch as other, possibly more convenient and economical methods of securing the parts together are already well known to the art, I do not wish to be limited to the method disclosed, the same being set forth herein merely as a method which is acceptable when the inven tion is used in connection with fabric covering material.

The invention contemplates the use of inner and outer frame members 2| and22; preferably constructed of light weight metal such as aluminum or alloys, held in place in pockets formed between the fabric l0 and the fabric forming the door II by fabric strips 23 and 24 sewed directly to the door and to the edges of the opening by the same stitches l1 and I8 as secure the webs I2- and 16 to the door and to the covering material respectively, and by the stitches I9 and 20 extending around the inside and outside of the frames. These'metal frames which are so formed as to correspond with the shape of the opening, are rigid enough to prevent any distortion either of the door or of the opening due to tightening or other change in the doped fabric or other covering material. In the drawing the larger or outer frame member 22 is shown as truss-shaped which adds stiffness to the frame and allows the same to be constructed of a lighter weight material, or of smaller weight proportions, either of which tends to lighten the structure which is of advantage in all types of arrcraft construction. It is essential that neither of the webs I2 or 16 be doped or otherwise treated or painted so that the flexibility necessary for proper functioning of the fastener will not be impaired. This is made possible due to the fact that the frame members are rigid enough to prevent any appreciable stress on the fasteners'tending to pull them apart.

The operation of the device is the same regardless of the shape of the opening. To open the door it is necessary only to grasp the tab of the slide fastener l4 and to pull the same around the outline of the opening. The reverse process closes the door. If one fastener only is used the corners between the straight sides of the door are rounded as shown so that the fastener may travel around them, but this fact does not in any sense limit the application of the invention for in the modification shown the angle between the sides of the triangular type of opening is 60 degrees or less which provides ample clearance in any space in which such an opening would be used.

Two or more fasteners may be used as desired or as may become necessary to meet requirements. The frame structure will be the same without regard to the .number of the fastening devices used for closure purposes so that the shape of thedoor will correspond to that of the opening. This is an important feature of the invention, as all covering materials are more or less subject to changes due to variable temperature, conditions of operation or to weather, and as stated above it becomes'essential whenever doped fabric is used.

The section of fabric joining the door with the covering material between the inner" and outer frames which has not been cut away serves as a hinge about which the door may be opened or closed. This section indicated at in Fig. 2 of the drawing may be reinforced if desired in the case of a much used opening. As previously set forth herein, both the door and the fastening device when in closed position, are flush or nearly so with the surrounding covering material so that no additional parasite resistance is introduced by virtue of the presence of the opening wherever it may be located.

Having described an acceptable embodiment of my invention, I wish it to be understood that I do not desire to be limited to the exact details shown and described, for as previously pointed out modifications coming within the scope of the appended claimswill be apparent and will occur to persons skilled in the art to which the invention appertains.

I claim as my invention:

1. In anairplane, a fabric covering having an access opening therein, a slide fastening device for closing said opening, flexible webs securing said fastening device to the' opposite edges of said opening, a rigid metal frame secured to the fabric on one side of said opening, and a second metal frame secured to the fabric on the other side of said opening, the said frames preventing the occurrence of stresses due to shrinkage of the fabric tending to pull the fastening device apart.

2. In an airplane, a fabric covering having an access opening therein of such shape that a portion of the covering forms a door adapted to close such opening, a slide fastening device for maintaining the door so formed in closed position, flexible webs securing said fastening device to the opposite edges of said opening, a rigid metal frame secured to the fabric on one side of said opening, and a second rigid metal frame secured to the fabric on the other side of said opening, the said frames preventing the occurrence of stresses due to shrinkage of the fabric tending to pull the fastening device apart.

3. In an airplane, a fabric covering having an access opening therein, a slide fastening device for closing said opening, flexible webs securing said fastening device to the opposite edges of said opening, a rigid metal frame secured to the fabric on one side of said opening, and a second rigid metal frame secured to the fabric on the other side of said opening, the said frames being truss-shaped to provide such a support for said covering that the flexibility of the webs of said slide fastening device is not impaired by shrinkage of the fabric covering.

4. In an airplane, a fabric covering having an opening therein, a door for closing said opening, a slide fastening device for maintaining said door in closed position, a flexible web securing one side of said fastening device to the edges of said opening, a flexible web similarly securing the other side of said device to the edges of said door, a rigid metal frame secured to said covering around said opening, and means for supporting said door in such a manner relative to said opening as to prevent any stress on the fastening device due to shrinkage of the fabric covering.

5. In an airplane, a fabric covering having an access opening therein of such shape that a portion of the covering forms a door adapted to close such opening, a slide fastening device for maintaining the door so formed in closed position, a flexible web securing one side of said fastening device to the edges of said opening, and the other side of said device being similarly secured to the edges of said door, a rigid metal frame secured to said covering around said opening, and a second rigid metal frame secured to said door adjacent the edges thereof, the said frames being one within the other when said door is in closed position.

CHARLES E. HATHORN. 

